I had dreadful razor rash no matter what method of shaving I tried (and I tried lots of different razors and the like too) so now I go to a salon and get waxed. I wouldn't recommend anyone doing their own waxing for bikini line or brazilian unless they are experienced- the potential for splitting the skin, causing painful bruising or just plain leaving yourself in pain is just too high.

Waxing can cause ingrown hairs if you aren't careful, but exfoliating and moisturising will prevent almost all of them.

Some things just aren't worth persisting with and if your skin is like mine resulting in rashes that last way beyond the day when you should be shaving again (and making shaving again impossible without major bloodshed) then I think that you're entirely justified in finding another way of dealing with the fuzz.