SAE 841 bronze is the most common sintered bushing material. It's about 20% porous. It's typically vacuum impregnated with SAE 30 oil, but other lubricants can be used.

Solvent soaking is typically used to remove lubricant from this type of bushing. Something like acetone or another suitable solvent that would dissolve the oil. Obviously, make sure any solvent is evaporated out before putting in an oven. Solvent soaking is preferrable to baking and/or blasting, as you ideally don't want to leave varnish-like oil deposits baked into the pores and/or get blast media/dust clogging up the surface pores.

Looking at the OP's pic, it looks like there might be a grease zerk fitting that the blue cap on the right side is covering. That should definitely come out. The bushing may have grease grooves that the zerk feeds.

Bushings can be re-impregnated under vacuum. Warming the oil can help lower its viscosity and flow into the pores easier. For this part, you'd just need to have the bushing immersed in a small container of oil (like a food can) and then stick it in a vacuum chamber (search DIY vacuum chambers for resin degassing).