Lately I have been using mineral spirits for varnish thinning and final brush cleaning, but in past times I have used regular paint thinner, turpentine (smells wonderful) and even kerosene just for cleaning brushes. Anybody use anything other than mineral spirits? Are there other similar products? On my shelf I have Acetone, MEK, brush cleaner (real nasty but it brought back a badly abused rock hard latex pro brush) and denatured alcohol for cleaning and shellac. And of course lacquer thinner which seems to be a combination of many of the above.