Pots with drainage holes to line shallow planters

[CarterBeatsTheDevil]

I have some of those shallow round planters that are probably best for spring bulbs. I wanted to use them for cacti and succulents, but they're glazed ceramic with no drainage and everything I have tried has struggled and needed to be repotted. I've tried lining the bottom of the pot with stones but this does not avoid sogginess.

I need an inner pot so that I can take out the plant to drain properly, but I can't seem to find any that aren't twice as high as the planter. Do they not exist or am I just lacking the right word to search?

What are the dimensions?

I have cut the top off a plastic liner pot when it is too tall. The edge might not be the neatest but will be hidden by the ceramic pot.

I second cutting down to fit. Nearly all my houseplants are in trimmed pots because I can never find a pot that fits the cover properly

chewing gum or blue tack and drill into the ceramic pot.

I drill holes in my ceramic pots and put pretty pot plates under them for drainage or let them drain in the sink before putting back in their place

Not sure - will measure in the morning. Though it sounds as if I might have to get the drill out!

Thanks everyone - really helpful!