Share 'What's the best way to de-bubble wax?'

I have a lamp that I bought off of ebay about a month ago. When it arrived the wax looked as if it had been shipped hot. Ever since the fluid has cleared up but the wax is extremely bubbly. It seems to get better with time but then it will get worse again. I was wondering what causes this (the bubbles) and what would be the best remedy? Thanks for your input!!