Yes it works great.

Key things to remember:

Clean all the grease and grime off you can, it will not penatrate it.

Remove as much rust as you can before treating, a wire brush, whire wheel, scotch abbrasive pads, etc.

Keep the car/parts out of direct sun when treating.

It takes time to work (24-48 hours for really crusty stuff) so a constant soak or stream of liquid has to be on the part being derusted, simply wetting it down will not work. I use buckets of Evaporust with submersible aquarium pumps (some pretty cheap ones out there) and clear plastic hose to route it over parts. If you get creative you can use a couple pumps and do multiple parts recirculating the fluid all around.

It doesn't last forever, it will remove a certain amount of rust then it becomes neutral, starting out as a clearish green/blue (like antifreeze) and turning almost black when it's used up.

When you are done derusting wash the parts off with solvent or thinner as opposed to water to prevent flash rust before primer/sealer is added.