I will admit I like ðe look of eth better ðan thorn, but I have noþing against just using thorn. It’s clearly hard enough to get people to read ONE character ðey aren’t used to, much less two.

ˈmeɪbi wi ʃʊd ɔl ʤʌst lɜrn ði ˌɪntərˈnæʃənəl fəˈnɛtɪk ˈælfəˌbɛt.

(Maybe we should all just learn the International Phonetic Alphabet.)