Being interested in DIY I often find on my hands grease, resin, and other hard-to-clean dirty.

Without any specific product there a very effective way to clean hands in this cases.

you just nead soap(liquid soap is easier to use and cleaner) and sand(or other abrasive powder.)

With Liquid Soap:

1)put a pinch of sand in your hand

2)add liquid soap as you would do normally.

3)mix them and rub your hands until needed.

4)then rinse your hands, if needed repeat.

With Solid Soap

1) Start washing your hands as usual with solid soap.

2) After a generous ammount of soap is dissolved on your hands leave the soap bar and add a pintch of sand in your hands.

3)mix them and rub your hands until needed.

4)then rinse your hands, if needed repeat.

Just a few more advices:

-Since your hands are supposed to be very dirty liquid soap allows you to avoid to contaminate the soap bar.

-Finer sand is to be preferred to more coarse sand because otherwise it could result too aggressive for skin.
Also aggressive soap is not recommended.

-You can also try to pre-mix liquid soap and sand. Settling of sand can occur especially with coarser sand and less viscous liquid soap. If sand settles down shake the bottle before use.