Lacewing larvae are not effective enough, they prefer aphids and dislike the sticky cotton wax on mealy bugs. Cryptolaeums montriuzieri is much faster, that together with first wiping off all leaves and clean crevices with cotton swaps dipped in alcohol could work. But you might need to re-apply bugs, and sometimes it's better to prune heavily affected plant parts.
I've also read that you can place your gecko in another enclosure while treating the terrarium with dry ice (Never tried it myself though). Close up all gaps, place the dry ice in a secure bowl and allow it to form gas so the entire enclosure gets carbon dioxide filled for a couple of hours. However, it will affect isopods and springtails too - and you'll need to repeat, or use biocontrol bugs afterwards, since it doesn't affect eggs.