It may not be cheap, but I am glad I got the dbx 376 Tube Channel Strip. I use it only for my vocal mic. It is extremely flexible and has an excellent de-esser that is very adjustable.
If you have a mutliband compressor you can use that as a de-esser. Set your attack to around 5ms and release to around 50ms, and then set frequency to around 5kHz-10kHz.
But I tend to use Waves de-esser. Its good.