It only works if you're smarter than the cow that the leather came from
I'm not sure which leather conditioner you have. Meguiars has one that comes in a squeeze bottle thats creamy, and another that is in a spray bottle. The spray bottle shouldn't give you too much of a problem, but the cream works so much better!
So, for the cream, get one of those round microfiber applicator pads from the auto parts store or somewhere like that. Apply a small amount
to your applicator pad. If you have an area that is not perforated, start there. This allows you to evenly distribute the product on the applicator pad.
If you have to, apply the cream to the applicator pad, then fold the applicator pad onto itself to work the cream into the pad. Then apply the pad to the seat. The less product you use, the less chance that you'll get that build up in those little perforated holes. So it's important to use a very small amount
at a time.
Afterwards, use a clean microfiber and give the seats a good wipe down. If you do end up getting a little product in those perforated holes, get a soft
toothbrush and lightly
brush the affected holes. This should bring the excess product out.
Hope this helps,