Ah, yes.  I forgot.  Astig only ... rgp's.

Let's see what's in their broth....

http://www.bausch.com/en_US/consumer/visioncare/product/gpcare/bostoncomfort.aspx

Boston Conditioning Solution:

Yup.  Preserved.

Boston cleaner:

Yup.  Preserved.

But there's a HUGE difference here: your RGP's do NOT act like a
sponge, so ...

1) You won't be slapping a soft lens -- hydrated WITH preserved stuff
-- onto your eyes;

2) A really cautious approach would be to simply rinse your RGPs with
PRESERVATIVE-FREE saline (even adding a drop or two into each lens)
prior to insertion;

3) IIRC, the PuriLens system works just fine for RGPs, too, though you
COULD do a little research.  It MAY take a month or two off of their
ultimate useful life .... fair trade to me for ease, thorough
cleaning, and disinfection, but ....

NB: the PuriLens is something like 99.9% effective on its own. Forgive
the analogy, but it's a little like the birth control pill. It's even
SAFER with a condom in the equation.

So ... you COULD use a PuriLens (like 15 minutes), and THEN bathe it
in the Boston conditioning solution.

Just do a thorough rinse before insertion.

HTH,

Neil
Anything BUT a doctor ;-)

I wear RGP's.  RGP's way more comfortable then soft lenses for me,
Boston eye drops work well during wear.
I also find sometimes excessive protien build up on them can make them
dry also. I would recommend using a protein remover once in a while.
Taking a break from wearing them helps too.
if they are still dry and uncomfortable I suggest talk to your eye
doctor. I've had to send my in for a polish once a year, clean them so
they are more comfortable.