If it was me, I would just pierce it with a fine sterilized need and wait for it to shrivel up which wouldn`t take too long because there would be no fluid to dissipate.
237SJ, with a fine needle the blister just closes up and fills up again, you could just get a pair of scissors and cut a hole to let it drain and just keep it clean, I have dealt with hundreds of blisters this way, they dry up really quickly that way.