I´m going to building my first gasser soon. and thinking of at some point going down the smoke route...

I´ve seen lots of people talking about home brews and also buying smoke fluids etc etc..
now I work in an events/tv company, and we have shelves and shelves of comercial fluids for smoke machines... even dry ice style that is (some how) heavy and actively sinks rather than floating (could be fun!!)

has anyone tried these types of fluids??? or should i get hold of an old silencer and give it a go???