I spoke about this before but, there have been three traveling girls in the past who have given me a hot water blow job.
It is exactly what it sounds like, they put some hot water or tea in their mouths, (hot like you would drink your coffee) then go down. they do this until the water cools a little and they swallow it then commence regular cock worship.
Every time I had it I got enormously aroused and had a super fuck session.
Just throwing this out there, you might have to experiment with it a while to get it right.