These toothbrushes from Tesco are 25p for a packet of 2.
That's a bargain!
The brushes are perfect for applying rustbuster fluid, the fluid can be scrubbed into tight corners and seams. I didn't do the repair above, it's an old repair which I tidied up and applied the rust fluid.
They can scrub out tight corners and clean electrical items.
This brush later applied seam sealer to a repair which I did do,
and it worked well. I would say get a couple every time you're in Tescos, they are very useful.
Bought to you as a public service, this site has no connection with Tescos,
other than pushing a trolley around every week!