Hot Showers Cost Money
Our entire group went about 12 days without a shower. We took advantage of a hot shower in our tea house on day two, and then we didn't shower again until we were almost done with the entire trek. After the first few days, tea house showers are shared and locked, meaning that if you want a hot shower, it's going to cost you. And it's not even guaranteed to be hot (our guide told us that it will most likely be very cold).
Going without a shower for so long was definitely hard, but even when we were desperate, we still didn't pay for a hot one because the insane cold you'd feel afterward just wasn't worth it (and if you have thick hair like me that doesn't dry quickly, you'd run the risk of getting sick). We leaned into being dirty, and I'm glad we did.