Font of knowledge?That kid was different.  Emile waited impatiently, checking his watch, tapping his shoe repeatedly on the ground, and, looking around for something entertaining. 

He was curious as to what he was waiting for around the bend, but he stood there anyway, respecting Figaro's command.  Like he had a choice.  He ran off before Emile could say a word, leaving him in the dust.

They were near the kitchen, so Emile expected food of some sort.  Bananas, tomatoes, eggs, and, cream pies were the only pranking foods he could think of, but he expected Figaro had plans to concoct something special.

He continued to wait, growing ever more impatient, even though when he glanced at his watch he noticed that only seconds had passed.

Figaro had slipped off down a corridor he and the Hufflepuffs all knew very well.  It wasn't very flashy, their entrance, but if you tapped out the correct rhythm on one of the giant barrels, it would open into a large round portal - the entrance to the Hufflepuff Commonroom. [1]

Once inside, Figaro trotted up towards his dormitory.  He had a word or two with his friends but didn't tarry about for a chat.  Instead, he quickly gathered a few things he'd need into a bag, and returned to Emile. 

"Good lad!"  Figaro tousled his hair, happy to see he didn't wander off.  "C'mon."

Figaro led the way without much conversation.  He led them up and out of the basement and to a quiet corner of a breezy corridor.  It was still pretty chilly being November and all, but the sun was out and they were sheltered from the wind.  Figaro took a seat on the ground and started taking things from his bag.

"I didn't invent this, but it's better than Weasley's and cheaper.  Plus you can make them yourself.  Here, look."  Figaro handed Emile what looked like paper balls with tails. [2]

"Careful," he added, although he knew he wouldn't have to. 

Figaro had begun laying out small vials and jars of pastes and powders, nothing with a proper label.  The ones that did said Sellaphix Apothecary.  He also had a wadded up stack of thin parchment squares, and two pouches of dust.

"Basically, you need to do two things - smoke and stank," he grinned.  "You follow?"

1.	New information according to Pottermore! link
2.	Like these, but about the size of a marble.  link

Thankfully, Figaro returned quickly and without much delay, mussing Emile's hair when he came back and telling Emile to follow.  He hated it when the older kids treated him like a child, but he would have to get over it, Figaro was helping him, so to speak.  So he followed without protest of his hair being disheveled.  They walked in silence for a bit, before stopping to sit beside Figaro.  He turned the what he assumed was the smoke bomb in his hand, being cautious as Figaro had advised.  "Yes, I follow.  What exactly are we using to make this?  And can't you make them bigger?  These are a little small," Emile said, a sly smile creeping across his face.
 

Figaro laughed and nodded.  "Aye, yes, bigger can be better.  But I like this size because they're easier to hold onto.  You can palm like six of them and they don't make awkward lumps in your pockets."

"Okay so here, take one of these and smooth it out."  Figaro peeled off one of the parchment squares and handed the stack to Emile.  He smoothed it out over his thigh and then set it down on the ground in front of him.

"First is fluxweed spores."  He held up a little jar with a cork in it.  Inside was a grainy red powder.  He uncorked in and carefully let some of it fall directly into the center of the square sheet of paper.  "Only a little.  This is going to help make the smoke dark. Here."

He handed it off to Emile and moved onto the next thing.

"Next is black silversage - that's where all the smoke comes from.  I think Weasley's might use doxy powder, but that's hard to get here.  So I use black silversage.  With the fluxweed the smoke's dark enough..."  Figaro explained as he took up a little leather pouch and again deposited a pinch into the center of the paper square.

"Next is stank.  Wait," he leaned over to check on Emile's progress.  "You got it?"