I ferment in an unmodified sanke in a freezer with the ebay controller from the DIY forum. I remove the spear to clean (oxy soak), sanitize and fill. Then I pitch the yeast and replace the spear.
I have a modified sanke coupler that has the check valve removed and attach that to the keg and a blowoff tube. After 36-72 hours (depending on style) I remove the blowoff tube and attached a pressure gauge and bleeder valve. I bleed excess CO2 regularly to maintain a pressure consistent with desired carbonation based on temperature.
There is a picnic tap attached to the beer side of the coupler for taking gravity readings and samples.
If you have the time, I highly recommend the information by WortMonger linked above (
http://iam.homebrewtalk.com/WortMonger). His information on sanke fermenting and pressure fermentation is very informative (and very long).
https://www.homebrewtalk.com/f13/closed-system-pressurized-fermentation-technique-44344/
After fermentation I cold crash and counter pressure transfer using CO2 to sealed kegs. When starting the transfer I pour some off into a pitcher but never get more than a cup of yeast.
Have been using this system for about five batches with success. Re-installing the spear is the hardest part, but by the third or fourth time it gets easier.