If you’re pronouncing it properly, the tip of your tongue should briefly touch the roof of your mouth – three times in the word “statement.”
I most certainly say “aith”. I do so (if I have to justify what just came naturally in my acquisition of language) because “th” is its own contained sound. Eigh-th. If I were to pronounce the “t” in any way by itself, then the terminal “h” is left dangling without its partner to complete the soft “th” sound. Eight-h? Doesn’t make sense.
For similar reasons of word construction, I pronounce panache45’s “width” with the “d” intact. Wid-th.
And because I’m in the mood to easily bristle (pronounced “brissle”) tonight, Beware of Doug, museums are “mu-se’ums”, human is “hyu-man”, involved is “in-volve-d”, and before you ask, library most certainly has two "r"s. It’s not a matter of “those people.”
Neither does your post. It’s perfectly possible to prounce the “T” sound and also pronounce the "TH"sound. So, I’m not really sure what you’re trying to get at here.
Right. So we put in an extra T. Wanna make sumpthin out uf it?
Sorry. I misspelled “uv.”
So it’s all a matter of belief as to the “right” way to pronounce eighth? Would that make those who don’t hold a definite belief on what is the “right” way eighthiests? 
- flees *
How about pronouncing two back - sixth? My old Physics teacher, Barry Turner, used to say “sick-th” which drove me bonkers.
Well! :dubious: You, my dear sir or madam, are clearly the Exception that Proves the Rule, hrrmph splut splmph. <twists bow tie nervously and shuffles off>
I pronounce it just like ath[iest]. No “t” sound at all.
I can’t recall ever hearing “eight-th”. Maybe I just haven’t been listening closely enough.
Are there any other English words where a situation with two consonants like this occurs?