Cleaning indoor concrete floor without damaging it
Use a solvent degreaser for concrete floors, following manufacturer's instructions, on the oily areas. Then mop with warm water mixed with a bit of liquid laundry detergent and let it dry.

If the treated area looks different due to alteration of the "waxy finish", use a hard floor wax remover on the entire floor, again follow instructions.

If you wish to restore the "waxy finish", apply a coat of hard floor wax finish. The cost of all the supplies needed should be less than $35.