A variety of completely different solvent chemistry types seems to be very helpful for premium cleaners. I've read guys say this several times in different places. Occassionally I myself have found that one kind of solvent does absolutely nothing and yet a different solvent readily pulls up the spot. I look forward to having insane heat too, for the spots that don't otherwise budge.
Googone.
I use the bottle with the small pee hole so its easier to put it all in one small spot. Use the cap to aggitate it. Rinse well.
Its the only spotter I use anymore besides 40 volume on stains.
What ive found to be a great spotter for small grease/ oil stains is a quick shot of brake parts clean quickly followed by hwe i keep a can on my van all the time. Picked up that trick keeping my repair bays carpet clean if at first it didn't come up with the prespray and rotary a squirt and another pass and it's always gone