I'm going to do a alcohol roll next weekend on a couple of hives. If mite levels are high, I'm thinking about vaporizing oxalic acid for control. I've been looking at a couple of vaporizers and am looking for recommendations from folks who've used them. A poster on Beesource is selling one that looks pretty well built. Anyone have any experience with this one? I've also looked at the one built in Canada ( I can think of the name ). It's been around a long time, any pros or cons with that one?