It's best avoided. Most hair removal creams are designed for the legs, and using them on genital skin is really not advisable.
I've used Veet, and it works quite well. I'd recommend something more suited for sensitive areas for hair on the penis, scrotum, anus, and grundle, rather than regular old Veet.
It can cause burns and it's not comfortable and it hurts when you use them 'down there'. When you use depilatory creams, it shouldn't be painful. When you use such creams, be careful and make sure you abide by the instructions. If it says not to keep it on longer than 15 minutes, than you should be getting rid of the cream at the 13-14 minute mark, just to be safe.
Use it, just be careful to not use longer than ten mins and make sure you don't have open skin. I do it all the time .
Because these depilatory products work by breaking down keratin. Keratin is what holds hair together but it's also a big component in the surface of your skin. In breaking down the hair, it can also break down your skin which results in a nasty (and painful) burn. The manufacturer of Veet and Nair makes a product for "sensitive areas" or the "bikini area". I do not recommend them for use around the genitals, though because of the risk of chemical burns. Trimming is always preferable but if you're wanting something more bare, waxing is a safer method than depilatories.