IIRC its creator said it's Lay-tech

The last sound being one that afaik doesn't exist in English. It's like the j in jalapeño but waaay guttural. It's the Greek letter χ.

Uvular fricative somehow reminds me of friction of the vulva.
They're nor related, are they?

Not to be too pedantic, the modern Greek chi is a voiceless velar fricative (or in some cases a voiceless palatal fricative) rather than uvular. The velar location is the same place English pronounces the letter k, uvular is a bit further back, more like the French r. It's a little confusing because the IPA uses the chi symbol for the voiceless uvular fricative even though Greek doesn't pronounce it that way. In Klingon, the voiceless velar fricative is written as H (I believe gh is a voiced velar fricative rather than uvular as well). I think the uvular consonants are q and Q. Apologies if my pedantry was unwelcome

That's how you can tell if someone is into latex (kink), they don't feel comfortable calling LaTeX (tech) by the same pronunciation around people.

It's actually a ch-sound, as in Bach. But Knuth also thinks the k-pronunciation is fine.