8 Helper had an idea of some sort (4)
9 Tar was cleansed by facing the answer (10)
10 It goes to show it's all about him! (6)
11 Usually rounded up in "Casablanca" (8)
12 Having done so, Khayyam's moving finger moved on (4)
13 Evidently it's where truth is delivered after swearing (7,3)
17 Sounds like what is used to get commercials into shape (4)
18 At first, support is mixed at this capital place (5)
19 Interrogation often conducted in a pub (4)
20 He predicts torn shorts? O yea! (10)
22 A shock partly opens the vessel (4)
23 And 'ere be a Scottish town (8)
27 Cream made of something that's not oil (6)
28 May be used for securing battering device - but it's falling apart nonetheless! (10)
29 If not well done, beef might be hard to find (4)