"I used to dive naked and it was even colder," recalls Hideko, who dove in a loincloth until she was 30 years old.
The sentence above contains ふんどし[1枚]【いちまい】
but wwwjdic has 褌一丁【ふんどしいっちょう】
To save some clicking and typing, online dictionaries say the following:
褌一丁 【ふんどしいっちょう】(wearing) a loincloth alone, nothing but a loincloth
一枚 【いちまい】 one thin flat object; one sheet
一丁 【いっちょう】(1) one sheet; one page; one leaf; (2) one block of tofu; one serving (in a restaurant); (3) (also written as 一挺, 一梃) one long and narrow thing (e.g. guns, scissors, spades, hoes, inksticks, palanquins, candles, jinrikishas, shamisen, oars, etc.)
The problem seems to be that a fundoshi is not only long and thin, but also flat:
Can I assume one can therefore use either counter for this item?