Hi Paul,
I would not put any tyres in Acetone that you would wish to use again.
Acetone is a solvent to most polymers and usually softens/degrades them quite quickly. You can wipe the beads of new tyres with acetone to remove mould release and bloom which will give you a better surface to stick the tyres to the rims.
The only time I would fully submerge tyres in acetone is when I require to reclaim the rims. Then I cut the tyre to recover the insert prior to putting the rest into the acetone bath. 24/30 hours should be enough time to loosen the bond and allow easy cleaning of the adheasive from the rim.
