You can remove products from advertising on Google Shopping ether in the data feed or Google Ads before showing you how I would like to take the time to explain a couple of things first.
Google automatically stops advertising products that are out of stock within 24 hours.
Removing a product for an extended period will negatively affect your historical ranking. It is better to let Google automatically control the ads, to reduce the adverse effects.
If you have a product that has low conversions but high CTR than maybe it’s not the problem of the product but an issue on the landing page or checkout.
If your product has high impressions but no clicks, maybe try to improve the following:
If all of the above have failed and you are not receiving the desired outcome, then excluding the product is a good idea.
You can exclude a product by item ID inside your Google Ads Product Listing.
Click on your Google Ads Shopping Campaign
Click on your product group
Click on subdivisions (arrow down) until you are at the item ID level, if you have not subdivided your products, have a read on how to implement subdivisions for your Google shopping campaign.
You can now click on the Max CPC column cell to change the bid option. Here you can choose to select exclude and then click on save.
By deleting the product from the data feed, please remember that the historic ranking could be removed. Ensure that when the product is deleted, you do not reuse the Product ID for any other products other than the same exact product.
I have written a great article on how to exclude a product in FeedArmy.