I remember  ( that in itself is an achievement )  back in the good old days  ( probly why I cant remember much  ) that the cure  for water/condensation in the tank was to chuck a bottle of meths  in the tank. I guess that a bit of alcohol in the fuel might be a wee bonus  here , but , there has to be  a time limit  as  there must be a point where to much absorbed water becomes an issue  as bertiesdad  said.

Here's a thing , spent the arvo chainsawing  back a few shrubs that  have got away , one was in the power line . When I gets the fuel container  of 50:1  Penrite 2/  and 95  , has been sitting round for a year , the fuel was yellow  the oil was green  but the mix is now  a bloody awful brown  where it used to be pale green , looks like (Madagascan) marine varnish , so I biffed it ( tipped on the driveway weeds ) , only about a litre  so not to much of a wrench ( Scottish heritage)