Ms Black, who was elected to the House of Commons the year after Scots voted to stay in the United Kingdom, said it was the most bizarre thing she was hit by.
Speaking in the second episode of BBC Scotland’s Yes/No: Inside the Indyref documentary, the Paisley and Renfrewshire South MP says “everybody got abuse” in the run-up to the historic 2014 ballot.
She said: “I had guys with Union Jacks running at me and things.
“The strangest thing I had thrown at me was a Bovril cube. But it wasn’t just any Bovril cube, they’d unwrapped it and flung it.
“I thought ‘that’s a lot of effort and it’s not even hurting’.”
Ms Black, who dramatically ousted Labour’s Douglas Alexander in the 2015 general election, added: “Strange things were happening everywhere.”
Former Scottish Labour leader Jim Murphy told the same programme that on one occasion a member of the public had put a 12-pack of toilet roll on the Irn-Bru crates he was speaking on and told him: “Big man, this is for you, you’ve been talking shite all day, this is to clean up the mess.”
Mr Murphy, who was hit with an egg when he took his street campaign to Kirkcaldy in Fife, said there were occasions when the behaviour of some campaigners was “absolutely intimidating”.
He told the programme a group of about 100 people wearing Yes stickers had turned up when he spoke in Motherwell in what he described as a “completely orchestrated” incident.
The former MP recalled: “We set up our table with stickers and leaflets, they just kicked the table over.
“Pushing and jostling, just staying one side of the law. But for people there it was absolutely intimidating.”
Blair McDougall, campaign director for the pro-UK, cross-party Better Together group, said Mr Murphy’s speaking tour of 100 towns across Scotland had to be suspended for a while “really for the safety of our staff”.
TV historian Dan Snow, whose father-in-law was the 6th Duke of Westminster, told how he came in for online abuse when he became involved in the campaign.
His Let’s Stay Together initiative featured celebrities including Sir Mick Jagger and Dame Judi Dench signing an open letter urging Scots to reject independence.
He said: “I would love to sit here and say I found it bracing and it only strengthened my resolve to get involved in things I care about in the future but it was brutal.”
Stuart Campbell, who writes the pro-independence Wings Over Scotland blog, said: “Other countries’ independence campaigns have waded knee deep in blood.
“All we did was occasionally call each other some names on Twitter. The idea that Scottish people are shocked by a few swear words is laughable.”
Yes/No: Inside the Indyref will air at 10pm on Tuesday March 12 on BBC Scotland.