RA flux will work fine if that is all you have, just clean the residue left over very well.

The solder wicks up the wire because the flux wicks up the wire before you tin. RA is more active and will allow a bit more wicking. Pour a bit of flux into a small open container, like a bottle cap/top stick it somewhere warm and let it dry out and get thick. Use just a little of that instead of the liquid when tinning wires and it will not wick as bad.

(you can use a hair drier for about 10 min to dry it out quicker, just be careful, and remember the dry flux is thinner when warm, so don't over dry it.)