I have repotted both my Lavender and Rosemary. Prompted by a handout; I saw a neighbor carrying a trash bin towards the dumpster and spied two nice clay pots inside. I said "are you throwing those flower pots out?" and she gave them to me. One was big enough to move the Rosemary up, and then I bought a new ten-inch pot for the Lavender.
The Rosemary plant has been looking poorly for a while, and I thought it was lagging behind the Lavender in growth (they're the exact same age) because I've been eating it so much! But when I upended its pot discovered this is one of the plants that got that bad mix of sand. The soil was very dense and heavy. I knocked most of it off the roots, gave it a fresh mix with plenty of perlite in it, and resettled into the new, larger pot.
Note: if you're going to use eggshells, be sure to rinse them first and dry thoroughly (a day or two) before crushing. Sticky membranes and yolk reside left inside the shell will make it clump together and have an odor (I've learned from error).