For that, you can't really beat TSP (Tri-sodium phosphate bought from Home Depot/Lowes or on-line). I filled a 5-gal bucket with a small box of the stuff and mixed well with really hot water, and dropped a upper and lower control arm in it....this was the first time I used it, and keeping the mixture hot really helps to do a better job.
Some people 'simmer' the pot, keeping it close to boiling, and it will suck the grease and dirt from all the nooks and crannies (Check youtube for videos). The upper control arm was done first when the water was hot....only took a couple hours of soaking and a light scrub with a scotchbrite pad when I pulled it out to get completely clean.
The lower control arm took longer as the bucket was outside and cooled too much...it still worked well, just took more work to wipe the REALLY THICK grease off the part.
Like the molasses method, it doesn't hurt the metal...but wear gloves as a precaution, or pull the parts out with some pliers and drop right into a clean bucket of fresh water (hot is better).
I think the 1lb box I used was like $4-5 from Home Depot.