Sprayers are specified for thin oils, and the difference between oils matters more than people assume.

Viscosity Is the Constraint

A fine nozzle can only atomise a liquid that flows readily. Thicker oils either produce a jet rather than a mist or block the passages entirely.

Most liquid cooking oils are thin enough at room temperature. The problems come with oils that thicken or solidify when cool.

Temperature matters as much as the oil: a kitchen at fifteen degrees changes how an oil behaves.

Generally Fine

• Olive oil, including extra virgin in a warm kitchen
• Rapeseed, sunflower, vegetable and other refined seed oils
• Avocado oil
• Light sesame oil, in small quantities
• Vinegars and thin infusions

Kitchen sprayers specified for thin cooking oils and vinegars, of the kind described at https://flairosol.us.com/, are naming the constraint precisely.

Problematic

Coconut oil, which solidifies below about twenty-four degrees and will set inside the mechanism.

Anything infused with herbs, garlic or chilli that has not been strained, since particles block a fine orifice.

Thick unfiltered oils with sediment.

Butter and any fat solid at room temperature, obviously.

Infused Oils Are a Safety Question Too

Worth flagging. Garlic or fresh herbs stored in oil at room temperature is a documented botulism risk, independent of any sprayer.

Commercial infused oils are acidified or otherwise treated. Home-made ones should be kept refrigerated and used quickly, or avoided.

A sprayer sitting on a warm worktop is exactly the wrong place for a home-made garlic infusion.

Cold Kitchens

Extra virgin olive oil clouds and thickens when cold, which affects the spray.

Warming the bottle in the hand for a minute usually resolves it.

Strain Anything Home-Made

Through a fine cloth, before filling.

One Oil Per Bottle

Mixing old and new is how residue builds.

Warm the Bottle in Winter

A minute in the hand thins oil enough to spray properly.

Avoid Coconut Oil

It sets solid inside the mechanism below room temperature.

Strain Everything Home-Made

Particles are exactly what a fine nozzle cannot pass.

Flush After Thick Oils

Sooner than the usual schedule.