In reply to douwe:
Ditch the flexbar, buy yourself a barbell which you can swap out the weights.
Load one side of the barbel with as much weight as you can control and with your arm bent at 90 degrees, rotate the weight inwards so you end up palm down.
It will hurt. You will feel a full warm feeling in the elbow.
Do this as many times as you can each day, you will find the pain at that joint angle goes after a few days. Even with exercise.
Find a different angle either closer or wider and repeat.
It takes a while to get all the angels but it worked for Dave McLeod, worked for me and a number of fellow climbers. FlexBar seemed to do nothing.