Mel,
 Yes, the sinucleanse is a plastic neti pot. The neti pot is also
sort of a trade name for the porcelin version marketed by the
Himalayan institute--it was originally developed for yoga, where they
want you to breath through your nose.
The Neilmed people also sell a blue plastic neti pot, as well as their
various squeeze bottles.
 The classic NeilMed is a squeeze bottle that holds about one cup of
solution. They market a saline mix you can mix with water for the
bottle--I fill it with my own. They also market a pediatric version,
the larger version that Susan referred to--16 oz--and a small version
for administering medications. They also sell various holders for
their products, on line.
 So, the neti pot is a pot that looks like a genie's lamp, that you
fill with saline, and with no positive pressure, allow it to flow from
one nostril, and out the other, with your head tilted sideways. The
NeilMed squeeze bottle is a bottle with a central tube and nasal tip,
that you squeeze into one nostril, with your head held straight up but
slightly forward, and it runs out the other side. One is low pressure,
the other involves some positive pressure, and the head positions are
different. My ENT likes the neti pot because he feels the head
position allows better irrigation. And he tries all the products
personally. He's anti the Grossan. He never really discussed the
NeilMed. I find that patients who think irrigation is gross will
consider the NeilMed, but the neti is too "far out" for them.
 Last time I was at Whole Foods, because my porcelin neti developed a
small chip, I found they had a steel version as well as the ceramic
one. And, the sinucleanse is a nice plastic neti pot that both my
daughters use because they're unbreakable. I use the sinucleanse on
vacation.
 I use the NeilMed when something is brewing, as I find the positive
pressure will sometimes knock something loose. The tell you not to use
it if your ears are blocked.
 Grossan doesn't like the neti pot because it doesn't involve
"pulsatile" flow and he thinks the head position encourages water up
the eustachian tubes. Once in a blue moon it feels like solution is
hitting my eustachian tube, and I just adjust my head position.
 So, that's my ramble on the two.
 They do sell the sinucleanse and NeilMed squeeze bottles in a lot of
major drug stores, as well as ebay, and direct from the manufacturer.
 Judy