Jan, I have never used FingerEase. I did use FastFret for a while. From my searching the Internet, I understand that FingerEase contains silicone which is a great lubricant, but not friendly if an instrument needs repair. It prevents finishes from sticking to the wood even after the wood has been sanded bare. Your use of it by spraying a cloth first and then putting in the strings/fretboard helps keep the silicone off the rest of the instrument. FastFret is a mineral oil based string/fretboard treatment.
Ken
"The dulcimer sings a sweet song."