Nair for bikini area

So, I struggle with razor burn when shaving and I tried everything to prevent razor burn but it never works so I bought Nair Hair Removal for the bikini area and I let it sit for about 8 minutes cause the package said not to let it sit for more than 10 minutes but I struggled because it was hard to wash the hair off and I was still left with some hair, now it just looks awful down there. Any tips for this?