Meaning of "put in all the salt and pepper"

Question

From Chapter 48 of Charles Dickens's Great Expectations:

“Mr. Jaggers was for her [Molly, Mr. Jaggers's maidservant],” pursued Wemmick, with a look full of meaning, “and worked the case in a way quite astonishing. It was a desperate case, and it was comparatively early days with him then, and he worked it to general admiration; in fact, it may almost be said to have made him. He worked it himself at the police-office, day after day for many days, contending against even a committal; and at the trial where he couldn’t work it himself, sat under counsel, and—every one knew—put in all the salt and pepper.

The 1933 OED oddly does not mention 'salt and pepper' but does contain the following entry for

salt, sb., 3.c. That which gives life or pungency to discourse or written composition ; poignancy of expression ; pungent wit.

Mr. Jaggers is depicted as being quick to punish ill-applied usages of words and other such minute discrepancies with noticeable vehemence, so could 'put in all the salt and pepper' refer to his imparting a certain flamboyance to the legal proceedings?

Answer 1

In addition to the OED entry for salt, there is this entry for ‘pepper and salt’

With reference to the pungency or biting quality of pepper: intensity (of feeling), spirit, vigour; ‘spice’.

To illustrate the usage the definition includes this quote from the 1887 New Orleans Lantern

But let me commence my assault on the offending ones and give them pepper and salt.

So combining ‘That which gives life or pungency to discourse’ with ‘ intensity (of feeling), spirit, vigour; [and] ‘spice’.’ might reasonably be interpreted as ‘imparting a certain flamboyance’ and vigour to the proceedings in hand.