Well done to both geevo & emmie, with geevo just in front.
Although there are twelve 6-letter possibilities, it's clear that E is probably 22. There are only two places where 22 is in the correct position for 'drivel' and one of those has a double letter (19), which rules it out.
The rest of the puzzle is fairly straightforward, although it claims to have a difficulty level of 9/10.