How do you clean a pail after use?

Hi,

I've brewed about 25 batches by now. Lately, I noticed something about my pails. My first pail had formed an off-white rough strips on the inside, mainly around mid-height. Initially I thought these were scratches from stacking pails in storage, but now my second pail starts to show the same signs.
So I think now that this is yeast and beer deposits that layer on the sides slowly. I think I might be cleaning my pales improperly

this is what I usually do : after transferring the beer, I rinse the pail. then using water and a paper towel I remove the hard deposits of the krausen ring and any other sticky trub/yeast/goo visible in the pail. I don't scrub or wipe the parts that aren't visibly dirty. then I put some sanitizer (Iodophore solution) close the lid and shake it. before usage, I rinse and sanitize again.

Do you think this was caused by faulty cleaning?
How should I clean a pail so it'll last?

I just spray with a hose, and use a sponge or washcloth/towel to get the gunk off. I sanitize before use. Mine don't look like new, but they don't look real dirty or anything.

Fill with hot water + oxyclean and let sit overnight.
Dump the next day and rinse really well and sanitize with Starsan.

could it be from a spoon or something when stirring?

I wash with dish soap and a sponge to get rid of the gunk + several rinses w/ hot water. then sanitize with iodophor.

You need to use some type of cleanser. I use Oxyclean and hot water and just let it soak . Really stubborn stuff gets a sponge . Now plastic buckets tend to go off color and it doesn't they are ruined just stained.

I pull the liner and rinse the bucket with hot water.

Rinse it with a hose, remove the spigot and clean, wipe bucket with a sponge, dry, reassemble.