Yup, same thing, and you don't have to buy another bottle to store later. Now, it's been DECADES since I bought sanding sealer but, as I remember, every new bottle had settled so there was something like 1/8" (or less) layer of powder in the bottom of a 4-oz bottle. That's not much powder.
Hey Bob, I've heard of castor oil in the dope but have never tried it. It DOES make perfect sense, however. That's also an interesting idea with the elmers & alcohol - gonna have to try it one day. All my C/L planes (7 are flying) are dope & silkspan (4 - more than 40 yrs old) or dope & SIG Koverall (3 - all 20+ yrs old), almost all (9, of which 6 are 35+ yrs old) my RC planes are monokote.