Vinegar! If there is leather or fabric near the clip, avoid getting vinegar on it. I would soak paper towels in vinegar and wrap around the clip. Leave for a few hours or over night. Really works!

Good to know how to remove rust. Thanks!

ask the company in case the collar gets damaged

Soak it in some white vinegar. Does an amazing job of getting rust off. Rinse and repeat if you need

Good reading the comments there really quite interesting!

Thanks for asking this good question; good to know the answers.

Some great tip here thanks.

CLR is worth a try for sure it seems to work well on a variety of things

I agree with CLR – its good stuff

a bit of steel wool should work and then try some metal polish to protect it. you could also use the metal polish to remove the rust as it is nice and gentle. ask at a car automotive place and they will have a gentle metal polish that should work.

Even wd 40 will help remove it

I would use some CLR and a bit of steel wool

Use vinegar and bicarb soda with some steel wool and the rust should come off. If not, CLR is brilliant for removing rust, and when you’ve finished, spray it with WD40 or similar, and you shouldn’t have any more rust. Good luck!

CLR is my go to product for rust. Just a little bit of scrubbing should get it off.

steel wool should get the rust off

Do you walk your dog at the beach? This could be the cause. Giving it a good scrub with steel wool and wd40 might help or yo can get rust removers at Bunnings.

I will be trying some of these suggestions, thanks.

I’ve heard of soaking things in coke too. Terrible stuff to drink but great for this!

there are some good comments here

maybe get some steel wool