"The sideslip is a staple of glider pilots, as you always want to come in a bit high then lose altitude rapidly in the final moments before landing."
Ehm, no. We are taught not to sideslip at all. We have airbrakes for controlling our glideslope angle. And when you pop the brakes, you're coming down steep
, no need whatsoever for slipping. If we want to get down even faster, we just increase our airspeed a bit. The only time we fly uncoordinated is when aligning with the runway just before touchdown in a xwind landing and in thermals, where a bit of slip makes it easier to center and seems to give a bit lower sinkrate (although opinions vary on this).
There were some gliders a couple of decades ago which had only a brake chute and no airbrakes. Those would be the exception.
Gliders in general do seem to slip and skid rather well, but it's not SOP, not necessary and not recommended. At least here, uncoordinated turns is
part of the curriculum and there is probably no form of flying which will give you better "stick and rudder" skills, including understanding of slipping/skidding. You can't get lazy and take your feet off the pedals while turning like you can in many GA aircraft. That's probably why the Gimli Glider captain chose to refer to his glider flying when describing how on earth he came up with the idea of slipping to steepen the approach.
On a sidenote, I've personally done some crazy slips and skids on approach in B735, SF34 and B738 FFSs, great fun but, again, very much not recommended. Especially not with a load of SLF in back as they'll spill their drinks and vomit quite a bit, especially the ones in the rear end. It sure helped the notoriously slippery SF34 come down at a high rate though!
Swept wings tend to create lots of roll moment when slipped due to the changed apparent lenght of the wings in the airstream. I also had an engine seize on me in the FFS right when I put on power to go around, due to a friendly instructor behind my back. The yaw created was all to easy to miss, but the roll moment was beyond what the ailerons could cope with. By the time I figured it out and got rudder in, it was too late. Way too late. Ouch. A very humbling experience indeed.
I thought I was doing good trying to avoid those airport hotels... and look at me now.