i too gave up on diffusers
spent hundreds
spent hours upon hours cleaning them
every which way but loose

every once and a while i'll use the plug in diffuser
with the felt discs
since that utilizes heat & electricity
i am not fond of it
i use it seldom

mostly, i just mist
and put "puddles" of oils in little ceramic/clay pieces
and drop oils on hankies and cotton balls and stuff them everywhere

i am also interested in knowing what the aroma stones are
probably the littel ceramic/clay pieces i use, huh?
some shaped like flower pedals
some like little angels with pouches that hang by a ribbon on a hook
and hold the oil