Think about using say 2x 10W wire wound cement resistors in parallel instead of a single high priced one. 55 cents each.
These don't need extra heatsinking.
Mouser Part #: 280-CR10-24
Mfr. Part #: 280-CR10-24
Mfr: Xicon
Category: Wire Wound Resistors - Cement filled Ceramic
Description: Xicon 10W 5% Low Ohm Cement Power Resistors 10WATTS 24OHMS 5%
Run two of these in parallel to get the 12 ohms you need.
I don't mean tail to tail one after the other. That is series.
Mouser Part #: 280-CR10-2.0
Mfr. Part #: 280-CR10-2.0
Mfr: Xicon
Category: Wire Wound Resistors - Cement filled Ceramic
Description: Xicon 10W 5% Low Ohm Cement Power Resistors 10WATTS 2OHMS 5%
Also run these two in parallel also to achieve 1 ohm total resistance in parallel.