Meaning and origin of British/Australian slang word 'tut'

The origin of the word 'tut' as a noun is, as of yet, unknown. The OED entry for Tut says:

Etymology: There is perhaps more than one word here. Of the origin nothing has been ascertained.

However, the use of the word 'tut' in the 'rubbish' sense may be supported by this definition from the OED:

a. Orig. in the Cornish tin-mines, now also in Derbyshire lead-mining: in the phrase upon tut (also by the tut), and attrib. as tut-bargain, tut-man, tut-work (also as vb.), tut-worker, tut-working, tut-workman: denoting a system of payment by measurement or by the piece, adopted in paying for work which brings no immediate returns, as distinct from tribute n. 3; hence, work of this character; dead-work.

The OED takes less of a cop-out on Tut, v. saying:

Etymology: A natural utterance; the spelling tut sometimes represents the palatal click (also spelt tchick n., tck int.).

Which may also explain the etymology of the slang word - being something that is just replaced for a word that is better left unsaid - a sort of self-censorship of more appropriate or cruder language.

Ultimately my guess would be that it's some combination of the two.

It would be nice if you could ask her, but 20 years later that seems difficult. To me it could have referred to the meaning "shit" as in "Just put some shit on your face and let's go!" but the speaker was in fact referring to makeup but didn't really care or wasn't interested in the result or any backtalk from the intended recipient :) (Canadian speaker but never heard the word before.)