Crossword Genius

In a jam, where to put acne cream? (2,3,4)

Ross

I believe the answer is:

on the spot

I'm a little stuck... Click here to teach me more about this clue!

'to put acne cream?' is the definition.
I can't tell whether this defines the answer.

'in a jam where' is the wordplay.
'in' means one lot of letters goes inside another.
'a' becomes 'one'.
'jam' becomes 'spot' (I've seen this in another clue).
'where' becomes 'th' (I can't justify this - if you can you should give a lot more credence to this answer).
'one'+'spot'='onespot'
'onespot' placed around 'th' is 'ON-THE-SPOT'.

Can you help me to learn more?

(Other definitions for on the spot that I've seen before include "Where acne cream applied" , "Under pressure" , "In an awkward predicament" , "At a particular place of action" , "Where snooker ball may be replaced" .)

I've seen this clue in the Sydney Morning Herald.
Want a hint initially instead of a full solution? Install my app