I did this on my 2.3 crank after I had it cryro-treated.
The crank was so slippery I could barely hold on to it and it was dry. I used it for about 1500 miles and when it was tore down to rebiuld it right, it was still perfect and the coating was still there.
Can't say if it really helps but it doesn't seem to hurt either and it is very resonable.
The crank was $175 for cryro and coating. That price also included treating the bearings.
I would love to do it to the turbo and may if it ever needs to be rebiult.