Recharging Cool Boots?

[MagicMelon]

I have an old pair of CoolSport boots, tried to use them today and theyre not swelling up in water, the crystals feel solid. Is there a way to recharge them? Maybe in hot water (dont want to try this yet on case it totally breaks them)?

 

[Red-1]

When they are thoroughly dry they can take 12-24 hours to recharge.