Gordon you're absolutely right. I toyed with the idea for several hours before deciding it was not a commercial option. As you say over time you will get corrosion in the chambers and breakdown of the Orings from thermal changes and end up with an oily mess. If you could solve this by using maybe a stainless housing and hightech polymers then the cost of machining and materials would again be prohibitively high. My original design had an intermediate oil chamber above the accumulator to act as an oil manifold, linked to each pin chamber... very similar to journal supplies in a crank case to try and maintain the same oil pressure to each bearing.
However when i realized it wasn't gunna be an idea i could develop i thought that it would be a fun lock for picking. You kinda want restricted oil flow for this. Each time your victim sets a pin and moves to the next stack and starts lifting, there will be a sudden pressure increase in the adjacent chambers that will hopefully just unset the previous pins!! kinda going round in circles

If i had access to some machinery id probably make one for a laugh and mail it to one of the Youtube regulars and see what they made of it!! Just counter bore all the extra holes you've made, hammer in some turned brass of right diameter and file and sand... they would do well to spot the modifications. As you say, the "working key" test might give away that something was up
