Back to a few pages ago.
I have successfully used a HOB and UGF with my Goldfish, It did a great job with keeping the tank clean, BUT it was not a planted tank (unless you count plastic plants).... so it would probably not work for your tank (I'm surprised how many people here have planted FW tanks).
I have only had snails in my SW tank and they are actually great cleaners of all unused debris including poop, leftover food and algae (I love SW snails and hermit crabs). FW must be different, they sound like a nuisance.. I have never had FW snails (other than in my pond).
I have also used a canister filter.. and LOVE LOVE LOVE it... I will not go back to any other type of filter (other than a sump if I get a SW tank over 150 gallons). I have a Fluval... and although it was pricey (around $200) it was well worth the money. I'm sure you can find one on Ebay for much cheaper than what I paid.
As for cleaning the gravel with a vacuum and getting the water back in your mouth from trying to start it.... all you have to do is completely emerge the whole vacuum system (including hose) in the tank let it fill with water and you are on your merry way to a clean tank with no fish poo in the mouth.
If you do not have a Vacuum I would really recommend getting one (they are cheap less than $10)... it makes water changes so much easier.... I actually would not know how to do a water change without a vacuum, because that is how I get the water out of the tank (I let the water and fish poo drain into a bucket and then flush it down the toilet).... How do you change your water and clean your tank without a vacuum?
What I would do:
1. Get another filter a canister or another HOB. It sounds like you do not have enough filtration for your system.
2. Buy a vacuum for the gravel
3. Weekly partial water changes
4. Check your water parameters before you do any of the above... test a week later and notice the difference.