Is there any fix besides replacing the whole upper control arm; the ball joint is only sold as an assembly w/the control arm ($150)

Would cutting a hole in the boot and injecting some penetrating grease (Wurth HHS-2000) work? I'd seal it as well as possible with silicone.
TIA, Tom

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RIP "Betsy" (Oo=*=oO)
'96 E 3 2 0 (W 2 1 0) M 1 0 4 (Totalled)
Spaces in sig so as not to screw up the SEARCH; every time someone searches for that MB they don't want my sig!

2004 Audi A8L
'98 VW Passat 1.8T 5M
'87 Alfa Romeo Milano 2.5L 5M
'67 Impala convertible, 327cid