My parts grew in scale by about 5mm after I did this. 
Yeah I’ve ruined several good prints by forgetting therm over-nite!
I bought a timer but the stupid thing doesn’t always ring…
And don’t leave them in there for weeks, or the whole alcohol vat will turn in to a gel!!!
Yikes! I thought it could do no harm to leave them in there longer? Is over night ok?
My parts will grow about 1mm if I leave them overnight. Instead, I set an alarm when I drop them in the bath, and pick them up 10-20 minutes later. I do the same with the second bath. This method works great for me. If the parts that are left in the bath, for an excessive amount of time, they will become rubbery, and depending on how they are laying in the bath, could create a bent/warped part.
Guys I got an IPA bath full of prints that have dissolved over months and its pretty dirty. Do I just discard it of can I filter the crap out and re-use it? Also is it ok to pour this stuff down the sink?
I use a conical sieve, into which I add 1 sheet of kitchen towel then a 150 micron conical paint filter and finally 1 sheet of kitchen towel again. This does a great job at filtering out the gunk and refreshing your ipa.
great thanks for the tip 
Yeah no sun in the uk to harden it off so this looks like the best solution.