You just have to do repetition.
He is 2, his memory is still not that great for the boring stuff. Keep tissues in your pockets, handbag, in each room, so you can grab them. Hand him a tissue and you do the big wipe.. then let him have a go at wiping.. then you finish him up. He will learn..
Tissue boxes are fine, but be prepared to sometimes have all of the tissue out of the box.. I personally did not care.. every once in a while.. I made our daughter stuff them all back in if she pulled them all out. Just part of thier exploring at some point..
I do not think it matters if the box is Boyish, do you?
But you can always do a project where he decorates it before you open it.. Or you could glue on firetrucks.. or whatever on there yourself..
Hang in there. He will get it, when you and your husband constantly are wiping his nose.