The Loctite thread sealant is one of my favourites. I think the one I'm using now is 567 - its a white paste.
If you were closer I'd have definitely taken you up on it. I don't go through a huge amount, probably only one 50ml tube every couple of years.
None of the tapered threads that I used it on leaked, it was the hoses at the ram that I only did the flare nuts up finger tight and didn't go back and tighten....