The wax solution seems to be the best way to get the squeezed out glue off
the Bessey bar clamps. But for those of us who already have plenty
deposited and well adhered to those bars, I have found my bench grinder
fitted with a good wire brush wheel to be effective in cleaning off the
hardened glue.

You just need to take a bit of care in manipulating the bar around the wire
brush wheel and wear plenty of face and eye protection.

Wade