i have people use my shop all the time and I have 1 rule you break the rule your out.
If you do ANYTHING that generates so much as a singal spark when your done working you take a 15 min or longer break before you leave just sit down have a drink what every just sit and look for sparks or some...
i didnt read this post all the way threw so sorry but had to post my 2 cents.
go buy a air rifle (high end BB gun) there all the talk on the gun sites/mags and SHOOT the damn things the ONLY way your going to get rid of them.
The other thing there is very few people that hate OUTSIDE cats more...
brake clean works wonders a friend had bad pine sap on his shinny black jeep and could not get it off I walked up sprayed small amount in a rag and wiped lightly cam right off I love that stuff truly a wounder chemical I sure it will take it off your floor.