Can you revive cigars?

Any cigar can be revived from a humidity perspective if it is done slowly and carefully. The issue is if the cigars where underhumidified for long enough that the oils in the tobacco have dried up. It isn't an issue of whether they can be revived it is an issue of if they are worth smoking after they have been revived.

On that one its try and see, I would guess that cigars at 55% would not have dried up near enough to lose any of their base oils and they will be fine.

Normally I would say take it slow but if you are comfortable they where at 55% then bringing them up to 65% isn't a significant enough issue to cause swelling or bursting. I always am concerned when folks wipe down the insides of their humi as I think that it is hard to get it up to RH% and then stop and hold but that is a personal preferance, I would just leave the water dish in (with a sponge in it for faster evaporation) till the RH got up then go from there, you might have to recharge several times as the cigars soak up the RH.

Just my .02