cleaning a range of metal items

[confused.com]

Hi all, I wondered if you can give me some advice. I bought some detector finds, very cheaply, so I assume they are worth nothing, as I would like to practice cleaning them up. They are particularly encrusted with a whitey creamy possibly clay like substance and one is particularly fragile. They are all metal. 2 have greenish tinges.

What would you suggest?

[cogar]

I suggest you post pictures of your items.

[confused.com]

Here you go

[Rauville]

If I was wanting them to look cleaner (not necessarily better)...I would boil the heck out of them in plain water.

[confused.com]

Just in a regular pan? What about the crumbly looking one? Also would you put them all together or do it separately?

Thanks for the advice.

[mart]

Except for the crumbly one,, I would get some naval jelly (rust remover) and cover them liberally ( just put it in a container and stick the items in it) and let them sit a few days !!   Then just soap and water and an old toothbrush to scrub off the rust !! Unless you want to get into a chemical bath thats probably the best you can do !!  For the crumbly one you can do the same as the others but after rinsing find a spot where the encrustation has chipped and literally pick it off !!  Try using a sharpened nut pick !! Works pretty well !!

[confused.com]

Thanks for that. Online it says we can't get naval jelly in the UK. Anyone from the uk know what I can use?

[Rauville]

Just in a regular pan? What about the crumbly looking one? Also would you put them all together or do it separately?
Thanks for the advice.

Personally, when its taken so many years for an object to acquire the patina that those have...I don't like to be the one that decides to remove it. But that's just my opinion.
Back to boiling. I'd try one item at a time (not the crumbly one). After getting the dirt off, you can change to clean water with a little beeswax and heat it up again to boiling to seal the surface of the item (I wouldn't use beeswax on coins). 

[kesgill]

Since this is just practice, I'd suggest you experiment with a few techniques.  In all cases, I would start with the warm water and soap bath to get off the dirt.  Then, you can try these (and I'm sure others have home remedies to share):
1. White vinegar (soak overnight) and scrub - you can dilute, if you think it will be too strong.
2. One part blackstap molasses to nine parts water - soak and clean with a brush or steel wool, if needed - I've used this off of another board a couple of times with relatively good results.
3. WD40 - wipe, and remove WD40 with paint thiner - probably most expensive method listed.
Etc...

I don't know about the crumbly one, so maybe that one should be reserved for just the water.  What you use should really depend on the underlying metal.  If you think you have any silver or gold or anything of potential value (like rare coins), I'd have a different answer.  These are just techniques to play around with and see what works best for your pieces.

[confused.com]

Thanks everyone. I've no idea what anything is. The bottom one in the pic is a coin. I don't think its British. The crumbly one has some lettering and some kind of hook or something on the back. I'll post some better pics of that if I can, I don't have a decent camera I'm afraid.

[bigwull]

Bicarbonate of Soda..or  Soda crystals...for the roosty ones...for the coin...good old Coca cola....still works fine.......

[confused.com]

Here's a couple of as close as I can gets