Review (4/5): Wash it immediately!
I used this for henna, it worked very well. It was easier to use, though I suggest building up a muscle or two in your hand if you want to use it over a half an hour, it can cramp your hand. I really like the large array of different tips, I've used about 4 of them so far and each of them work very well.
The only bad part is that, when I tried washing them out after every use(cause henna can rot), they were difficult to clean. The wider, fully plastic tips were easier, but some of the tips had to be soaked to get everything out of them, and the lids were difficult to fully clean as well.
Overall, good product, fulfilled its use, but a tad challenging to clean.