Paul I think you have a bunch of disgruntled employees or ones who like to listen to you wonder why or how. I could see how that would be fun.
What has saved me more foam guns than anything and it is not really dangerous but you need to do it in a safe place definitely outside.
When I have a gun stop up I open the gun all of the way, point the gun in a safe direction and take a blow torch and run it back and forth on the barrel until you melt the foam in the barrel. When the foam starts run it until the foam is flowing freely while it is still melted.
The cleaner will not touch cured foam unless you melt it. You can do the same as above but replace the foam with a can of cleaner and it will clean out melted foam and your gun will be like new.
I have tried other brands of foam because fastenal and kwikset carry them but they have been terrible failures and waste of money.
I would buy my foam by the case and if you don't use a lot split it with another wco. You each get a free can. I would only buy it from businesses who move a lot of it because you get foam with expiration dates way out.
The two best deals $ wise and freshness are our two friends Phil Nichols and the tireless self promoter ska Alan Huot at wcs.
A use that may not be a fix that the home owners would want to keep forever or try to sell their home with but works and you can charge accordingly and will last.
Those squirrels or birds that pop up the vinyl soffit or eat a hole thru in dormers where it meets the roof. The roof is usually steep and hard to work there. Hard to reach with ropes or chicken ladders the people already have s 600 dollar animal removal bill and you really don't want to step of the ladder.
The animal removal is done I've had a temp. plug over the hole I'm ready to close it and get my money. I explain what I am going to do to the customer and what I am going to charge.
If they agree I take a 6 ft snake tong, a frog gig, a decoy retrieval hook, an extendable paint pole something that will reach the hole with out me stepping off the ladder. Maybe use a little piece of hercules putty from WCS to hold the wire mesh plug that I stuff into the hole. Sometimes it takes two or three pieces or two or three tries but finally I have the hole completely blocked with porous wire. I duct tape an up to 10 ft. piece of pvc to my gun barrel put it up to the wire patch pull the trigger completely covering the wire and blocking all air flow. This causes the hole to disappear to the animals nose or feeling of air flow. Only an animal with a fillet knife can penetrate this patch and I tell the homeowner that so that the roofer or whomever won't be saying whotf or [Please excuse my language... I'm an idiot] did or is this. They can take a fillet knife and remove it without renting a power tool.
If foam is exposed to uv rays you have to paint it. Then it will last as long as concrete.
I did a pigeon job on a decorative historical building missing a piece of decorative metal that was going to require a 2000 dollar custom piece, a craftsman and a lift to put it up. I cut the back out of a newspaper tube screwed it over the hole so the pigeons could drop out but not return. The majority moved down the street to the court house. Seven heavy pressure birds chose to sit on the ledge like I expected. I went over late at night told the police I was going to shoot the pigeons with a pellet rifle and my cheap night vision. An ND3 laser mounted on the scope. We all looked at it and one went with me to be a look out and try the night vision himself. I love the sound of a pigeon hitting the concrete.
The owner agreed that we would try this. I put a big chunk of foam over the wire patch and after drying took a few knives and cut the foam to match the rest of the building. Then painted it. From the ground it looks like a 5 thousand dollar fix. He loves me and recommends me everywhere.
Even if I am going to brake metal, put wood or vinyl over it I put foam or caulk behind the repair as part of the exclusion. It stops air flow and animals like fire are attracted to and follow air flow
One last foam use fill your ladder rungs to stop the singing on rack.