Gets angry when the hair drier is used on? (12)

'hair drier is used on?' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'gets angry when the' is the wordplay.
I cannot really see how this works, but
'when' could be 'on' (I've seen this in other clues) and 'on' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
This explanation may well be incorrect...

Can you help me to learn more?