im not sure how big of gap you are trying to seal, but for recaulking a normal joint, here is how I do it, and would suggest you try, to see if it works better for you....
silicone can work, but if you want it to last you need to prep the surfaces more than if using some other caulkings... personally, I think proper surface prep is about 85% of a successful job...... Its my practice to always clean the surface well with soap and water, then after it dries, I wipe it with alcohol, then i use a very narrow piece of scotch brite pad and scrub the line where the caulking is going to be.....
then i mask it off with tape, staying about 1/16" of an inch away from the edge of the gap, on BOTH sides of the gap.... then i wipe it with alcohol again and let it dry good...
then I apply a small bead of sealant down the gap, and then push it into the crack, (without pushing so hard that it wipes it OUT of the crack) with my finger as I fair it out...... then pull the tape immediately after fairing it out before it has a chance to skin over... if it skins over, the skin seems to always stick to the tape, and as the tape is lifted, it will pull the skin off the uncured sealant, which you dont want to happen. but if you get the tape off before the caulking skins over, the tape comes off leaving a clean, straight edge on the caulking..... then with a wet finger, I very lightly fair down the tape edge of the sealant.... it makes a professional looking job and will adhere to the surface forever...
as to the brand/type of caulking, I will leave that for someone else to say, as when I need to reseal something I use marine sealant, which may be better for some things, but is too adhesive for other things that may need to be taken apart without damage...
one has to know the properties of the sealant they plan to use, otherwise it could be a problem as some point...