This is a great question of how many towels. People are always wanting more for less work in the end via washing them on your own time. While i am in agreement of the above comments, I recommend you get different colors for the different applications you are performing. In addition, there is a new product out called Soft Landings Towels. (yes, it's mine). But I think the question is how much time and effort will it take to wash your towels vs you using the towels as a base with a disposable one on top to use and then dispose of.
You would have to play around with what works best but i know that in the nails industry, you almost never have to wash that many towels. For esthetician and waxing, give it a shot. Try and see what works. Sweet Squared has the towels for sale. They also give free samples. Please let me know what you discover. I'm all for networking and educating.
Hugs and softness,
Kathy