Laundry scent booster crystals

Salt crystals soaked with fragrance and tossed into the wash for a lasting scent on clean clothes. They add scent only, not cleaning.

Use only skin-safe fragrances, because scent stays in fabric that touches skin. Skip strong sensitizers like cinnamon bark and clove.
Wear gloves when mixing concentrated fragrance into the salt.
Crystals look like bath salts or candy. Label the jar 'Laundry use only. Not for bath or eating' and keep it away from children and pets.
Never add chlorine bleach to a load that has a vinegar or citric acid rinse. Bleach plus acid releases chlorine gas.

Steps

Put on gloves. Put the salt (and baking soda) in the bowl.
Drizzle in the fragrance a little at a time while stirring, so every crystal is coated. Add colorant now if using.
Spread it on the lined baking sheet and let it dry for 1–2 days, stirring once or twice, until it's dry and loose.
Store in an airtight labeled jar.
Use 1–2 tablespoons per load, sprinkled into the empty drum before the clothes, not in the dispenser.
Wash as usual. The salt dissolves and the scent carries through the wash.

Crystals clump together: Too much oil or not dried long enough. Spread it out to dry longer and stir in a little baking soda.
Oily spots on clothes: Undissolved oil hit the fabric. Put crystals in the empty drum before the clothes, and use less fragrance.
Scent doesn't last: Pick fragrances with heavier base notes (musk, cedar, vanilla) and skip high-heat drying, which drives off scent.