The proper prep can make a big different to how your Fleshlight adult toy feels. Here's the usual MO:
Fill the sink full of warm-hot water
Remove the insert from the casing and sit it in the sink for 5 minutes
Repeat if you like, or for thicker inserts
DON'T use the microwave or boiling water
Pop some wipes nearby to help with the cleanup - you'll want to get the lube off your hands to get a good grip on your adult toy
Slather the inside with water-based lube only; silicone-based lube will react with the adult toy and melt it.