One , hang dry.

Nope, bacteria lives everywhere in and on your body, we call it skin flora, that said the bacteria lives off your dead skin, oils and other skin bacteria and yeast so showering reduces it's rate of reproduction, and most of it wont thrive on a towel but yeast is a part of your flora too and it will thrive on a moist towel.

The next issue that most showers are in a room with toilet that is regularly used, so humidity stays above the rest of the house's base level from a bowl of water in the same room and it disperses shit loads of bacteria from your colon and whatever bacteria festers in your toilet when it flushes.

Best practice is a new towel every shower but a 1 time reuse isn't the end of the world, and this would be 3 times if you don't have an active toilet in your shower room and add another day if you live in an arid climate.

If your skin flora is well balanced and you don't get acne or other skin problems then just keep doing what you are doing if that's one towel every 7 days then go for it, if you have skin problems change your towels and sheets more often, shower more, exfoliate, moisturize, no fix? could be a food or textile/polymer/wood/detergent/soap allergy you are ignorant of, or it could be your washing machine or dryer is dirty.

Hygiene is primarily about health but secondarily about being socially presentable because hygienic practice tells others about your health and self preservation instincts.

Can't you tell? Is something wrong with your gaydar?