IMO, actually, we have, at least, 3 solutions:
Simple "Parametric" stuff:
1) Charging 2 caps in // and discharging them in series...
A very old idea. Kinda "Tesla Switch". Claimed to be working by some people and useless
More elaborated "Parametric" stuff:
2) Charging 2 caps in // via a coil and discharging them in series... A less old idea.
"Double Parametric" stuff, a more 'tortuous' idea:
3) You energize 2 coils while they are in the 'few Henries' configration.
Then, you let them giving back their NRG to the two caps (in //) when these 2 coils are in
the 'lot of Henries configutation'. In the attached picture: 0.45 mH versus 227 mH one.
V = L.di/dt + i.dL/dt. No?
The CCT is much more complicated indeed. But worth to be though about, IMO. NO?
A real measurement of one of my bifilar coil:
All the Best from Brest,