1st what chems were you using. Prespray and rinse?You are right i need a defoamer. My recovery tank was foaming up (1 bdm only, rsf prespray, plus pre spotting, then robs alkaline rinse). I can imagine doing three rooms and the foam would go into the vac pipe!Yeah you dont want it bunched up at inlet. I put it on and use stick or pencil or something to push it through so i can grab it from inside. And pull it in. So theres only bout 2” left just enough for cuff to slide over. This way there is more then enough hanging inside. Once you get going it should take the shape of the barb inside. And will expand to the size of your arm when full of lint. Just be careful of foam. Any foam and these become foam generators. Suck up a palm full of powder defoamer and poof foams gone. Even canister filter you will be using these socks or paint filters to catch debris. You will experience some cfm loss. But trade off is less to no fuzz stuck in your motors.
Get yourself a jug of powder crystaline defoamer. If in a pinch and need something quick and cant get to store. Liquid fabric softener will knock down foam. Just suck some up hose. Preferably before starting so it can coat hose and tank.
Powder defoamer works instantly.