Hi, I have drilled holes in our compost bin, just as you say. Here's
the longer story...

We have one of those plastic compost bins, and to be honest haven't
found them that good, most likely I think because of the difficulty in
getting air into the compost, the small(ish) volume of material, and
the way that, if you only have one bin, you have to keep adding new
unrotted stuff to it. It never just magically comes out of the bottom
looking brown and crumbley as the people who make them seem to suggest
it does.

Anyway, I now have two other (wooden 1m x 1m x 1m) compost bins. I
fill one over about 4-6 months, then take out the contents (this adds
air, mixes the material and allows me to adjust the moisture level) and
put it into the next bin. 4 months later when I need to move the next
batch I take the first batch out the the second bin and place in the
third - my old plastic bin. The plastic bin holds a smaller volume,
which is why I put it last in the cycle, because the rotting process
has caused the compost to reduce in volume quite significantly by this
stage. We have drilled holes in the sides of the plastic bin at the
level of the compost to aid aeration just like you suggest and I try to
give it a bit of a stir occaisionally too.

I wouldn't say this is the best composting system by any means, some
people definitely go from raw material to mature compost much quicker
than it takes me (which is a bit more than a year) but it's a huge
improvement on what I was trying to do with the one plastic bin!!!

We tried this after someone else commented how they felt the turning of
the compost was the biggest factor in how long the compost took to
mature. I can't disagree.

Hope all that's of interest, good luck,

Clare.