Green’s Dictionary of Slang

shake hands v.

In phrases

shake hands with an old friend (v.) (also shake hands with the baby, ...the fellow who stood up with me at my wedding)

to urinate.

[NZ]G. Slatter Pagan Game (1969) 162: Went to the hooter to shake hands with an old friend.
[US]Maledicta IX 194: This article and series devoted to sexual slang would be incomplete without some notice of catch phrases, both British and American: […] shake hands with the baby (urinate) [Ibid.] 195: […] I’ve got to go shake hands with the fellow who stood up with me at my wedding (urinate).
[US]G. Carlin GeorgeCarlin.com [Internet] Urinate: shake a sock / shake hands with an old friend.
shake hands with the unemployed (v.)

1. to urinate.

[Aus]B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 100: I gotta go and shake hands with the unemployed.
[Aus]J. Wynnum I’m a Jack, All Right 33: [I] reckoned you’d been let down again by your Japanese bladder and had taken yourself off [...] to shake hands with the unemployed.
[UK]P. Reading 5x5x5x5x5 1v: He’s just sunk six pints [...] and he needs a wee – / calls it ‘Shaking hands / with the Unemployed’.
[Aus]G. Seal Lingo 88: Bodily functions do not escape the Lingo [...] Urination may be a piss, slash, shake hands with the unemployed, giving the wife’s best friend a shake, pointing percy at the porcelain, and so on.

2. (also shake hands with the bloke who enlisted with me) to masturbate.

[US]Maledicta IV:2 Winter 192: We also come across specialized terms in the male masturbation phrases such as […] shake hands with the bloke who enlisted with one.
[UK]Roger’s Profanisaurus in Viz 87 Dec. n.p.: shaking hands with the unemployed euph. A wrestling bout between Hand Solo and the pink Darth Vadar; wanking.
[[NZ]McGill Reed Dict. of N.Z. Sl. 220: unemployed, the The penis, during period of sexual hibernation].
[UK]in Guardian 14 Aug. [Internet] Since my wife left me for the window cleaner I’ve been shaking hands with the unemployed on a regular basis.
shake hands with the wife’s best friend (v.) (also shake hands with one’s wife’s best friend, give the wife’s best friend a shake) [wife’s best friend under best friend n.] (orig. Aus.)

1. to masturbate.

[Aus]B. Humphries Traveller’s Tool 60: The memories could come flooding back […] while you were having a pee or shaking hands with the wife’s best friend.

2. to urinate.

[Aus]B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 20: I’ve got to shake hands with the wife’s best friend!!!
[Aus]R. Aven-Bray Ridgey-Didge Oz Jack Lang 11: Needing to shake hands with his wife’s best friend he adjourned to the Angus Armanasco to splash the boots.
[Aus]C. Bowles G’DAY 5: When an Australian goes to urinate [...] he most often goes for a piss, a slash, or a leak. He hardly ever shakes hands with the wife’s best friend; syphons the python or points Percy at the porcelain.
[Aus]G. Seal Lingo 88: Bodily functions do not escape the Lingo [...] Urination may be a piss, slash, shake hands with the unemployed, giving the wife’s best friend a shake, pointing percy at the porcelain, and so on.
[UK]Guardian 17 Dec. 56/2: ‘I’m off now to shake hands with the wife’s best friend’.