As long as the drainage holes don't get clogged up and blocked then yes it will work. Remember to feed the plant though as it wont get any replenishment of nutrients unless you provide them.

Remember that the whiskey barrel has to drain, as well. Roses won't grow in a festering, anoxic bog.

Whiskey barrel has no top or bottom in it ! The well drained water butt sits inside the wooden barrel containing the rose. Which will be well fed !!

Okay...the picture that I am getting now, is an empty rain butt with holes, embedded in potting compost in a well drained rain barrel, with the rose planted in the compost. Is that correct?

It’s a empty wooden whiskey barrel no top no bottom. Inside this is a 100 litre plastic water butt filled with manure , john innes no3 and multi purpose compost with drainage holes drilled in it . Inside the plastic hope to grow the rose .

Obviously my imagination needs a tune-up! :)
That sounds pretty good, to me. Where I live, I'd have to leave out the manure, since that is a little strong when the temps go over 45º C. It should work better in the UK, though.

Agree about leaving out the manure initially. You could top dress it with well matured manure after a while, eg after the first year. Incidentally there will be enough fertilizer in the John Innes for several months so you won't need to feed straight away. My preference for fertilizer then would be a specialised rose food rather than a general one which might have too much nitrogen and not enough potash..
Also make sure the water can drain away from the barrel or the wood might start to rot.

Many thanks