Your question is "framed" a little bit wrong,
A "Hooked" breech is a method of installation/removal of the barrel, versus a "Straight/Solid tang" breech.
With a hooked breech the tang is a separate piece mounted to the rifle allowing the barrel to be removed alone.
A solid tang is actually part of the barrel and needs to be removed with it.
Along with those types is the way the barrel is installed in the stock. A hooked breech is usually used with wedge keys that hold the barrel in the fore-end for easy removal,
,while straight tangs are usually "pinned" into the stock, making barrel removal a lot more involved.
Don't fret, staight tang rifles have been being cleaned just fine for centuries while still installed on the gun, it's just a different yet simple method to accomplish the same results.
Both can either be a "Patent" chamber breech or a direct channel breech.
In another topic member
@Idaholewis shares cut-away photos of a "hooked patent" breech;
Patent Breech trouble.