How to you clean buildup from within bottles without bleaching labels?

[Jonesy_sa]

Gents

I did a few brews which formed allot of buildup in the bottoms which appears all on the sides etc once drained. I tried hosing them under pressure to no avail.
These bottles have custom labels printed on the same stuff as vinyl car stickers and I don't want to damage them.

How would you clean them? I have bleach and hydrogen peroxide but think they'll damage the label?

Also, has anyone found a good brush that cleans everywhere in the bottle?

 

[Brads Biabs]

Always rinse bottles as soon as you empty them just hot water and bit of detergent.
Better still go to kegging so much easier.

 

[Jonesy_sa]

They are already empty however I did try hot water when fresh to no avail :-(

 

[Hyper.Intelligent.Fish]

https://www.bigw.com.au/product/brigalow-home-brew-bottle-brush/p/202327/

 

[mongey]

Make a bucket of sodium perc and fill them and let them stand for a couple days.
I’m yet to see some crud it won’t break up eventually.