Can someone tell me how to clean these please? Pic included!

[politicalcorrectnessisgreat]

What do you use to clean them?

A good soak in very hot soapy water. Scrub (chisel maybe required) then rinse off and clean with brasso?

Thank you I will try that

You could try bar keepers friend powerful stuff and can be used in coolers.

*cookers

Definitely bar keepers friend, it's amazing stuff.

Crumble up a dishwasher tab and make into a paste to leave for few hours or soak over night in a little water

I mean take the parts off the cooker first and soak in basin

Soaking in a slightly alkaline solution would work.

Soda crystals or, if you have this stuff round the house, caustic soda BUT ONLY A VERY MILD SOLUTION BECAUSE THAT SHIT IS LETHAL.

Strong alkalis are what's used in most oven cleaners and are often the cause of severe burns to users arms