Drilling Holes In Cache Pots

I have bunches of beautiful ceramic cache pots that I can't use outdoors because they have no drainage holes. I'd like to drill some drainage holes in them. I can see doing it two ways, either using a masonry bit with my drill or a grinding bit on my dremel.

Anyone had experience with this? Also, is it best to go from outside in or inside out? I'm think from outside in. An egg can take more pressure from the outside than the inside .. since cache pots are round, I'm thinking that would hold true for them.

Any tips and tricks would be welcome.

Thanks!

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