I don't use Sally's thinned, but I do make my own glue for the finish of a jig. Mine soaks in and doesn't leave a hard spot. I mix Clear High Gloss Lacquer and MEK 50/50. You could use a different thinner, but I like MEK because I can use it for several things and it dries fast.
Also forgot mention fingernail polish is just a Lacquer! So you can also use the High Gloss Lacquer for other things like over eyes to protect, just use at full strength for somethings. I bought a Qt of each years ago and still using from the same ones.