Just my opinion. I think buckets with holes in them are a waste of a good bucket. 1 bucket to ferment and 1 to feed from. Use a scoop with holes in it to scoop don't worry about liquid not draining. After scooping from main bucket add dry feed to soak up liquid. Leave it a little sloppy and leave set till the next feed time should be 24 hours later the liquid will soak in and also ferment the new dry feed. next day you will have moist not wet fermented feed stir in the mother and feed.
Experiment a little to see how many wet scoops to how many dry for your needs.
https://www.backyardchickens.com/t/644300/fermenting-feed-for-meat-birds/1630#post_9755259
I don't like the buckets w/holes either. For me it's because the feed I buy is made to order from a feed mill - not pellets. It has both Fertrel and fish meal in it which is just powder. When using the bucket and hole method, those powders end up sifting down to the bottom of the external bucket and don't stay mixed into the feed.

When I strain it out like you're talking about, I reach right down to the bottom of the container and be sure that I'm getting a good mix of everything when I put it into their pan.
Pigeon - could you post a link or photo of your strainer spoon? I did some looking around and wasn't happy w/what I found. Wondering what yours looks like.