Probably best using a tt finder or F101 or being honest by the time you've found all the drops you need and had to sell the other finds etc it is probably just as cost effective to buy them
Im pretty sure they need to be looted to count for Rais?
Though since DSEC9 is indoor mining, its probably cheaper to travel to Toulan and mine Nawa there.
Yamato fly Monria>Toulan tonight, and comes back about 2 hours later Toulan>Monria for 6PED total for the night.
Leaves you plenty time to get your Nawa.
Nawa drops are wasters, so can be found almost anywhere, from TT finder to whatever, pretty much anywhere on the planet.
Hope this helps.
E~