The biggest problem with the new washes is that they are still new and it's gonna take time and experimentation to get used to them. For anyone. I've had a lot of play time with them from even before they were released, and while I can say I've never tried the Baal Red on Liche Purple, I'm simply guessing that it may not prove to be great. It may work, but lighter colours on darker ones is more Glazing, rather than washing, and is FTW for tying together highlights and basecoats.
What I may suggest, as it worked for me on my Vampire test piece, is the Purple Wash (Leviathan?) on top of Dwarf Flesh. That gives a vaguely natural look. Using Tentacle Pink may add the old school Genestealer look from Space Hulk. Either way, darker washes on lighter colours.
As far as creating a slimely look, or wet look, the Gloss Varnish paint pot has been used by many for a long time. Simply paint on. Perfect for LEDs and lights and such. Something I saw fairly recently by a long time pro was painting on layers of PVA glue if you want depth (like in a mouth of a Carnifex say) and then a brush of the GW Water Effect or similar product. Being really clever, and this ISN'T hard, but is fiddly, is to get a short light hair. Pluck an eyebrow or something and make it blonde! Then (and here's the tricky part) PVA it to the finished paintjob where you want slime. Imagine it's flocking the base with grass, only one blade and on it's chin! Then, build up many layers with PVA glue. Takes time, but it's so easy. Finally, when you have your trickly of slime, Water Effect it once or twice for added reflective watery look!!!
Sounds pro, but I've hopefully broken it down to simply understand and you'll be amazed of how simple it is. REALLY REALLY EASY!!!!