Flux for removing LGA socket
Type of flux isn't really important when desoldering.
It is very important for wicking solder (as it removes oxides from the solder wick, aiding in solder wettage of the wick.)
I realize that there are plenty of videos from quite famous youtubers that absolutely drown the electronics in flux when (de)soldering, but there is absolutely no need for that. Solder flux removes oxides that build up on any exposed metal. This oxide prevents the intermetallic layer to form properly and you will get weak joints when soldering. During desoldering there isn't really any point to remove oxides at the surface of the solder joint.
The key to a good desolder, especially of LGA and BGA, is even heat and enough, but not excessive heat. Preheat the board to 70-80 degC and use hot air at 350-380 degC.
Never, ever use force. Heat+force will ruin your pads.
The component should just smoothly come off. Any amount of prying with a tweezer or screwdriver will ruin both your part and board.
Once the part is removed you can (carefully!) clean with solderwick drenched in flux, but once again, you don't need flux on the board (but a pool of flux on the board drenches the solder-wick, so why not.)
Finally the board can be cleaned with IPA.