Mealy bugs ?

Something built a nest on some of my cacti. Not 100% sure what it is, but the usual suspect is mealy bugs. After googling around, it seems that isopropyl may be a good solution. Luckily I had a bottle of ESSO Fuel Condensate Remover (thanks, ESSO). I simply put the pipe from a spray can into the 100% proof isopropyl, and gave them a shower. Isopropyl, like most alcoholes, evaporates quickly. So far this seems to be a good treatment, repeating it once a day for a few days should do the trick.