Giving some sheen or shine to pt/pd prints seems to be the Holy Grail for some folks. I have tried all of the methods mentioned so far and none of them make enough difference to justify the trouble IMO. If you want shine, just put the prints in a frame behind glass and you will get plenty of it!!
Sandy
Although I don't see the smilely faces, I can only presume you are joking Sandy (although I agree - I've tried it and the difference in dmax isn't worth the bother to me. As Arentz says - you'll never achieve the high dmaxs of a silver paper, so get used to it or switch to silver. Let the eye be fooled into accepting the dmax on Pt/Pd that you do achieve)
They're not trying to make a shine, but change the surface characteristics. By changing the surface from a diffuse matte to something less difuse, they are going to achieve higher dmax. Its there on the paper already, you just can't see it.
This effect was well know in even Silver paper -- you could get a higher dmax out of glossy paper compared to the exact same emulsion in a matte or semi-matte surface (pearl, etc back in the days when Kodak offered the same paper with different surfaces).
this will work with most alt processes where the wax and solvents don't change the image chemically.
On the subject of which wax:
Sexton has used Renaissance wax for years on his already-glossy prints, particularly on his teaching prints (although his purpose is to extend the life of his teaching materials: to repair the minor abrasions that happen). So Renassance wax, with its microcrystalline structure should work similarly with Pt or Pd.