Hellou.
I'm polish programmer and front-end developer with 13yrs of experience, specialised in osCommerce stores.
I was writing offer in other of your project but it has ended, so will try to give more detailed description this time.
For 6 years i was working as lead developer in computer store, with dozen of wholesellers integrations.
We had to keep offer clean and nice, so from time to time products had to be expelled from db.
It was done after quarantine. After two weeks without any updates products were turned off. After definable number of days, there could be removed for good. Mostly when there was no connection with orders, they could be removed from db.
Later , with SEO policies change, we stopped deleting and came to setting them up as temporarily unavailable, as it was giving better Google results.
As for images, you will be able to define, if it should check and remove also images defined in description of products that supposed to be deleted.
In your case you can define how and when products and their images can be removed, and you will get such script.
You will be able to test it on copy of your db, to be sure all works as needed.
If you need to know / hear more, im here to answear in both english and polish.
All the best,
Trygon eXtreme