glad to answer your question s, as i too had many doubts with with method.
yes, it was a full sized towel provided by the hotel.
i did one shirt at a time. did the burrito twice per shirt. the towel was a bit moist afterwards but i think i could still have dried another shirt. i am a very small person though so it could be different for bigger shirts.
travel towels are on the thinner side so am not sure if they can take as much moisture.
A6 notebook + mechanical pencil are an indispensable part of my travel kit. i always worry that i will lose my phone at some point so important addresses are written there.
pen and paper can be very useful in places with a different language/writing system. there was a time i looked for a specific product that i had a difficulty describing. fortunately, i met a local who can speak english and asked him to write down the local name of the said product. it can be done on the phone but i find that older people are more comfortable writing with a pen and paper.
for everyday, i use my phone s native notes app for quick jots but still carry with me a notebook and pencil.