bipolar aluminum caps

We use tons of surface-mount tantalums, in the 5 to 10 cents each range. I derate them 3:1 if they are on regulator outputs; their ESR behavior suits many regulators just right. They have practically no inductance.

I don't use tants on power input rails where lots of surge current is possible.

Well, in the Asian lexicon they are two different things.

Nonpolar (NP) is used for crossover networks and such like-designed to take AC.

Bipolar (BP) is for occasional reversing (input to a comparator or a controller that can be + or -.

BP is cheaper and smaller for the same voltage/value if you can use it.

--sp

You can just put a resistor in series. At least a few ohms. The more the better (and the worse the filtering).

--sp

Well, i have had a number of the old style wet electrolytics that were working at the time for about 10 years and most were only low in capacitance. All they needed was some liquid rejuvenation and forming to continue operation to specs for 5 years. The vents on top were there to allow this.

Also,the old Tek scopes (10 years or so) some of which had been standing in the weather (LA area) were re-formed by easy and simple well-established techniques.

Apparently you need more education.