Não.
Nada na seção Rituals, no Ritual Caster feat ou no Ritual Casting das classes diz nada sobre ser capaz de guiar alguém. Além disso, observe a parte enfatizada abaixo - ela afirma explicitamente que o spellcaster deve ter um recurso que permita que ele faça isso. Rogues não.
Certain spells have a special tag: ritual. Such a spell can be cast following the normal rules for spellcasting, or the spell can be cast as a ritual. The ritual version of a spell takes 10 minutes longer to cast than normal. It also doesn’t expend a spell slot, which means the ritual version of a spell can’t be cast at a higher level.
To cast a spell as a ritual, a spellcaster must have a feature that grants the ability to do so. Classes that can cast rituals as a class feature include Barbarian, Bard, Cleric, Druid, and Wizard. The Ritual Caster feat also allows any class to cast ritual spells from one of the following classes: Bard, Cleric, Druid, Sorcerer, Warlock, or Wizard. The caster must also have the spell prepared or on his or her list of spells known, unless the character’s ritual feature specifies otherwise, as the Wizard’s does or while using the Ritual Caster feat. Pact of the Tome Warlocks with the Book of Ancient Secrets Eldritch Invocation may also cast any ritual spells they find and add to their book.
Note que, da parte enfatizada , você também não pode apenas guiar alguém para lançar um feitiço que ele não tenha - se é isso que você estava pensando.