Your social security must be a lot more generous than mine!
Well, my best advice is to buy some of the Squirrel Buster feeders. I have several of them. The squirrels recognise them from other yards, I guess, because they do not even try to get the seed from the Squirrel Buster feeders. The feeders are reasonably priced for the quality, the superb customer service, and the lifetime warranty on all parts. What you will save in the cost of seed will more than make up for the cost of the feeders.
Unfortunately, cleaning up bird poop on a deck or railing, on the feeders hung in trees, in the bird baths, etc., is part of the price we pay to enjoy seeing them and listening to their songs. I do not enjoy cleaning up behind them, but once again, it is a small price to pay for the joy they bring to my heart every time I see them in the yard and around the house. If cleaning up behind them is more than you feel you can or want to handle, then stop feeding them. There is no other solution aside from possibly hiring someone to clean up behind them.
Personally, I would NEVER feed squirrels, and I cannot understand why anyone would feed them. They may look somewhat cute, but basically they are just rats with a hairdo. If you use the Squirrel Buster feeders I mentioned, and if you STOP trying to feed squirrels, and you resign yourself to the maintenance of the deck and the feeders as part of the necessary experience of feeding and enjoying wild birds, then I think you should be pretty happy.
Feeding squirrels....
ETA: I have had other bird lovers tell me that the black oil seed from Walmart and from Tractor Supply (to name two) is about as good as Wagners for half the price, so that is where I will buy my seed this Autumn and Winter. 👍