So far as I'm concerned: yes, PCB holders are useless if you happen to have four arms.
I'm always wishing I had four arms when I solder. I don't happen to have four arms so it's nice to have something hold the PCB steady while I hold a tiny little SMD component with tweezers in one hand, a 350C soldering iron in another and the solder in my remaining hand.
If you're holding the solder, soldering iron, and part, then something is wrong. No need to apply unmelted solder to the part. For SMT soldering, this is called "dry soldering." Youmay end up damaging parts that way, since the head capacity of the molten solder helps prevent overheating. If you heat the part and pad directly before feeding in solder, you risk overheating the part, especially for some chip parts like capacitors that are prone to delamination.
Try:
1) apply flux
2) apply small amount of solder to the chisel tip (no pointy tips)
3) holding the part in place, transfer molten solder to fluxed pad/lead joint, and allow to flow.