So the other day I was reading the preview chapter of サムライ８八丸伝, the new manga by Masashi Kishimoto who previously created Naruto when I came across a sentence which said "次は趣味いっとこ”. I was really confused about the word いっとこ. The context is that a character is listing off a bunch of wishes to a shooting star, and he says this as he is switching topics to 趣味 related wishes.
I asked a Japanese friend, as well as my Japanese teacher what it means, and they both say in this context いっとこ is the same as the volitional form いこう, but I can’t seem to find any source for that online (not that I’m doubting two separate native speakers). I was wondering if anyone knows where I can read more about this form, or has anything further to add than that? Is it a dialectal thing? Can I use it with verbs other than 行く?
Also as a side note I find it interesting that Japanese use the same metaphor as us for “moving” to the next topic.