【Rid】 , 【clear】 ,  【unburden】 ,  【disabuse】 ,  【purge】  are comparable when they mean to set a person or thing free of something that encumbers.

【Rid】 is a rather general term but is likely to refer to concrete or specific matters which are burdensome or pestiferous.

【Clear】 is likely to be used to refer to tangible matters which obstruct progress, clutter an area, or block vision and may be used also in relation to ideas that hinder progress.

【Unburden】 typically implies a freeing of oneself from something taxing or something distressing the mind or spirit, in the latter situation often by confessing, revealing, or frankly discussing.

【Disabuse】 is appropriately chosen to refer to freeing the mind from an erroneous notion or an attitude or feeling making 【clear】 straightforward thought difficult.

【Purge】 may refer to cleansing out of or purification from whatever is impure or alien or extrinsic. In political matters it may suggest ruthless elimination.