Rinsing with the Mother Liquor...
Use the mother liquor to rinse solid residue (product) from the recrystallization flask after you have swished and dumped.
The mother liquor is the liquid that collects in the filter flask as you do your vacuum filtration. Since the mother liquor was in intimate contact with the solid product, it will NOT dissolve the product if used again.
Pour the mother liquor in the filter flask back into the flask containing untransferred product. Then perform another swish and dump adding the residual product to what is already in the filter funnel.
Using the mother liquor is much better than using a fresh amount of solvent since it can dissolve appreciable amounts of the solid product.