In the past I would partially fill a keg with sanitizer, swish it around, push some out of the dip tube to make sure there is sanitizer in it and then dump the sanitizer out. I'd then usually let the keg sit upside down for a while to let more drip out.
When I do that now the floating dip tube escapes and then I have to touch it to put it back in which kind of defeats the purpose of sanitizing. How do you guys deal with this?