I basically only use Loon Aquel. It doesn't leave a slick unless you put too much on and it supposedly masks human scents. I think it floats flies longer than anything else I've used.

Frogs Fanny, IMHO, doesn't last more than a few floats at most (for me) and where I live you lose 1/2 the application and part of what's in the container from just by putting it on one fly because it can be windy here. I guess "can be" is an understatement <g>

Mixing it with fly drying beads seems to help.