What's sand
?
You can get "Gravel Guards" that will prevent most sand from getting in the boot but anytime you are wading deep into soft sand in good current they'll still probably fill on you. All that said, I still really like stocking feet with felt sole wading boots. The felt is good for marginaly slick surfaces and you can break out the korkers after the fact.
Now if you got two pair, say Hodgmans, you could get one boot foot for ultra sandy conditions and boot foot/wading shoes/Korkers for when fishing the morraine and Ledge....