bottle cleaning

I had many bottles that were really dirty, and I kept them in my basement for a long time.

I knew the time will come to clean all of them, so yesterday I decided to do the job.

I took all of them to my kitchen (over 100 bottles) and first I rinsed them with warm clean tap water. I noticed that the stains inside them were nasty - whole living world of mold, bacteria, big germ party going on inside

I decided not to brush at all, but just put some vanish oxy action (european version of oxy clean) inside each one of them, approx, one gram of powder per bottle, and then just filled them with water.

do you think oxy clean will clean them well after soaking like this for 3 days?

do you have any suggestions what to do next?

Id make sure to get and gunk out of there. I used a garden hose when i got some dirty bottles then used a bottle brush, then boiling water then santise. Cant be too careful when it comes to home brew. No need to wait a month to find a 5 min job cost you a batch of beer.