First, let's acknowledge the obvious: if your skis are submerged in real glop it will be nearly impossible to swivel, twist or pivot them. The glop provides too much resistance.
The harder you try the worse things get. If the skis won't twist all that rotational energy you pushed at them has to go someplace else. Some of it gets absorbed by your knees, which aren't built for swivelling. The rest shoots back up into your hips and torso, throwing them out of balance. Now you're cartwheeling, possibly with damaged knees.
So then, what to do?
Violent unweighting to pivot your skis above the snow (aka, "Leap & Land") can work but it's pretty exhausting. This works best on steep slopes, where gravity does the work and linked edgesets are sometimes the safest technique. If you're skiing a 40+ degree chute in heavy glop, letting your skis run risks straightlining into the rocks/trees/cliffs. Leap & land can be a survival technique.
OTOH, linking Leap & Land turns on gentle slopes will wear you out pretty quick and it's not necessary. Try this instead:
- keep your feet close together so that your skis act like a single platform; nothing's worse than two submerged skis going in different directions!)
- spread your hands and arms VERY wide, for balance
- stand in the middle of your skis; this helps you manage the sudden accelerations and decelerations that are inevitable in cruddy snow; don't fight them, just try to get back to your centered position (it's usually easiest to slide your FEET back or forward as necessary, rather than trying to toss your upper body backwards or forwards)
- make no sudden movements (your skis won't budge, remember?, any sudden energy inputs will just toss you off balance)
- from a downhill-trending traverse, sink down so your legs are a bit flexed (you're not unweighting, just doing a gradual semi-crouch)
- plant your downhill pole and let your upper body follow it downhill; your skis are now outside of the new turn, your body's inside
- now, strongly - smoothly - gradually, push both skis away from you - out to the side and into the glop
The harder you push, the more they'll bend. The more they bend, the tighter the arc they'll make: you're riding the bent, submerged planks and their arc defines the turn radius. It won't be a short radius turn, but the faster you go the better this works and the easier it is to be balanced.
Once you pass the fall line and approach the end of the turn, your legs will be pretty extended. Now's just relax your legs and let them flex up beneath you into the next semi-crouch, plant your pole and flow into the next turn.
These turns can be practiced on any sort of soft snow. They look a bit weird but they're actually quite easy to do and link. In truly heavy, non-steep glop they may be the only thing that works.