as w/any mental illness, i do think the key to success, is earning their trust.
as i've stated, we've had many pts who refuse or are unable to adequately keep themselves clean...
and just would not trust anyone.
then along came a Godsend of a tech, who was blessed with many gifts and established meaningful rapports w/these type pts.
as with most pts, these pts need to know they're in control.
a big part of compliance, imo, is babysteps, being truthful (which means never, ever trick/deceive them) and involving them in the process every step of the way.
sit them on a shower chair, keeping them covered at all times.
let them feel the water on their leg/arm, so they know what to anticipate.
do not ever, ever spray their face.
when it's time to wash their hair, give them a washcloth to hold over their eyes and keep shower nozzle only on their head.
explain to them, what you're doing/washing, encouraging them ea step of the way.
go as quickly as possible, yet making it therapeutic.
when it's over, dry them completely and dress them quickly.
when they recall the (positive) experience they had, they just may not be as resistant the next time around.
even though are techs are the ones who do the showers/baths, i often will do it myself, if i need to see their skin, or, are known to be labile.
but before any of this transpires, the pt is going to have to trust you in the first place.
if all else fails, then chemical sedation may be necessary, but certainly not on a weekly basis.
finally, document your proverbial behind off, at all attempts to intervene and subsequent refusals.
they're a tough bunch, and decidedly, for good reason.